2 LEDs and one pin left

[Jumper]

and what makes the current not flow thru any of them when the pin is in INPUT?

[mackrackit]

From a data sheet.

Setting a
TRISA bit (= 1) will make the corresponding PORTA pin
an input (i.e., put the corresponding output driver in a
Hi-Impedance mode)

http://en.wikipedia.org/wiki/High_impedance

[sayzer]

1,0
0,1
0,0

LEDs on these states won't be possible by one pin.
Instead, use 4017 with one pin.

I have an example here:
http://www.picbasic.co.uk/forum/showthread.php?t=6548&

[rsocor01]

Jumper,

You can use "one LED" only like the one in the link below. This is pretty much two LEDs put together. It is a red-green 3mm LED.

http://futurlec.com/LED/LED3RG.shtml

1,0
0,1
0,0

LEDs on these states won't be possible by one pin.
Instead, use 4017 with one pin.

I have an example here:
http://www.picbasic.co.uk/forum/showthread.php?t=6548&

However, the bad news is that Sayzer is right. You can't get three states "0,0", "0,1", and "1,0" with only one MCU pin.

Robert

[ScaleRobotics]

However, the bad news is that Sayzer is right. You can't get three states "0,0", "0,1", and "1,0" with only one MCU pin.

Really? Because I am using Dave's code on a 18F26J50 (3.3 volt) with no resistors, and it works like a charm. Red, Blue, off

BLINK:  
     HIGH PORTA.0 
     PAUSE 250 
     LOW PORTA.0  
     PAUSE 250   
     TRISA.0 = 1 
     PAUSE 2000    
     GOTO BLINK

[rsocor01]

Really? Because I am using Dave's code on a 18F26J50 (3.3 volt) with no resistors, and it works like a charm. Red, Blue, off

BLINK:  
     HIGH PORTA.0 
     PAUSE 2500 
     LOW PORTA.0  
     PAUSE 2500   
     TRISA.0 = 1 
     PAUSE 20000    
     GOTO BLINK

DOH,

The trick is in the TRISA.0 = 1 to get both off (the 0,0 state). Nice!

Robert

[Darrel Taylor]

I think this page explains what Walter is doing pretty well ...
http://www.batsocks.co.uk/readme/p_tut_led16.htm

[sayzer]

Really? Because I am using Dave's code on a 18F26J50 (3.3 volt) with no resistors, and it works like a charm. Red, Blue, off
Attachment 4604

BLINK:  
     HIGH PORTA.0 
     PAUSE 250 
     LOW PORTA.0  
     PAUSE 250   
     TRISA.0 = 1 
     PAUSE 2000    
     GOTO BLINK

Nice trick indeed.
How about RED and BLUE = ON ?

(without ".....Of course the square wave signal would have to be interrupt driven off of a timer in order to have both LEDs on at the same time. " )

[ScaleRobotics]

Nice trick indeed.
How about RED and BLUE = ON ?

(without ".....Of course the square wave signal would have to be interrupt driven off of a timer in order to have both LEDs on at the same time. " )

Nice one Sayzer! I guess that is four states for one pin!